Synchronous drive system and embroidering machine employing the same

ABSTRACT

There is provided a synchronous drive system which employs, in place of conventional mechanical elements, a pair of belt-driven unit mechanisms: The unit mechanism essentially comprises a pair of stationary shafts arranged at a predetermined interval, a slider means movably disposed between the stationary shafts, and a belt member trained around the pulleys of the stationary shafts and slider means. The synchronous system thus features its unique power conversion from rotatative movement into linear movement. There are further provided an X- and Y- axis directional drive system and a multiple-head embroidering machine both utilizing this synchronous drive system.

United States Patent Sasaki 1 1 Sept. 16, 1975 SYNCHRONOUS DRIVE SYSTEMAND 2,760,454 8/1956 Lambach 112/90 EMBROIDERING MACHINE EMPLOYING3,456,608 7/1969 Marcus 1 12/102 3,468,268 9/1969 Rolaulfs 112/86 THESAME Inventor: Hiroshi Sasaki, No. 48-14, 2-chome, Denenchohu, Ota-ku,Tokyo, Japan Filed: Sept. 6, 1974 Appl. No.1 503,904

[30] Foreign Application Priority Data Sept. 20, 1973 Japan 48-106677[52] US. Cl. .1 112/86; 112/102; 112/103 [51] Int. Cl. D05C 3/04 [58]Field of Search 112/102, 103, 83, 86, 9O

[56} References Cited UNITED STATES PATENTS 1,154,871 9/1915 Marschalek112/83 1,274,119 7/1918 Wetter 112/83 2,030,495 2/1936 Bretschneider"112/86 2,091,727 8/1937 Bohmann et a]. 1. 112/102 2,709,976 6/1955Lambach 112/90 Primary Examiner-Alfred R. Guest Attorney, Agent, orFirmWilliam Anthony Drucker [S 7 1 ABSTRACT There is provided asynchronous drive system which employs, in place of conventionalmechanical elements, a pair of belt-driven unit mechanisms:

The unit mechanism essentially comprises a pair of stationary shaftsarranged at a predetermined interval, a slider means movably disposedbetween the stationary shafts, and a belt member trained around thepulleys of the stationary shafts and slider means. The synchronoussystem thus features its unique power conversion from rotatativemovement into linear movement. There are further provided an X- and Y-axis directional drive system and a multiple-head embroidering machineboth utilizing this synchronous drive system.

5 Claims, 16 Drawing Figures PATENTEB SEP 1 6 m5 SHEET PATENTED W5 3.905.3 1 5 SHEET 5 F|G.7 (a) PATENTEB l W5 (if Ou Ei m Est SYNCI-IRONOUSDRIVE SYSTEM AND EMBROIDERING MACHINE EMPIJOYING THE SAIME BACKGROUND OFTHE INVENTION This invention relates to a synchronous drive system whichis capable of causing a plurality of moving elements to make linearmotions in synchronism with one another by means of rotary driving, andalso to an automatic multiple-head embroidering machine adapted forindustrial use and controlled by numerical system or the like whichemploys said synchronous drive system for effecting its embroideringmovements in X- and Y- axis or longitudinal and transverse directions.

Conventionally typical drive systems which are used to change rotarymovement into linear movement mainly include mechanisms which employassemblies of rack and pinion, and of screw and nut or the like. Thesesystems have widely been utilized from old times. However, they have thedisadvantage that with these systems structurally it is difficult tocompletely eliminate backlash between the individual parts and abrasionof some of the parts, however precise these parts are made. As aconsequence, if these mechanisms are directly applied to a synchronousdrive system, the system will have a deal of difficulties due to suchdisadvantage. Further, the conventional systems of this kind aregenerally complicated in structure, are large in scale enough to be highin moment of inertia, and are easily influenced by any errors inpositioning or assembling of the surrounding parts or elements, thusresulting in difficulty in their designing, high manufacturing costs,and hard maintenance, etc. The result of embroidery by an automaticembroidering machine is influenced by the accuracy of movement of amaterial to be embroidered on such as cloths with respect to the machinebody. Further, in an industrial-use embroidering machine which isenquipped with a plurality of arm beds for making embroidery on theirrespective frames simultaneously, it is required to equalize thedisplacements of the individual cloths to one another, but with theembroidering machine having the conventional type of synchronous drivesystem it is extremely difiicult to maintain above the level theaccuracy of the displacements of the cloths to be embroidered on.

BRIEF SUMMARY OF THE INVENTION The present invention has been devised inorder to eliminate the above-mentioned weekpoints possessed by theconventional synchronous drive system and the automatic embroideringmachine, and therefore it is a primary object of the invention toprovide a synchronous drive system which is intended to cause aplurality of moving elements to make linear motions in synchronism withone another by means of rotary driving, and is characterised not only byits highly accurate driving ability enough to ensure highly synchronizedmotions of the moving elements, but also by its wide application andsimple construction.

A second object of the invention is to provide a X- and Y axisdirectional synchronous drive system which is particularly adapted foruse with an automatic embroidering machine in which it is used to movegiven moving elements in X- and Y- axis directions, i.e.. inlongitudinal and transverse directions, and is characterised by itshighly accurate driving ability, wide application and simpleconstruction.

A third object of the invention is to provide an automatic multiple-headembroidering machine adapted for industrial use and capable of beingnumerically controlled, which employs said X- and Y- axis directionaldrive system, and is able to produce very nicely finished embroideries.

A fourth object of the invention is to provide an automaticmultiple-head embroidering machine adapted for industrial use andnumerically controllable, employing said X- and Y- axis directionaldrive system which comprises pairs of rotary drive mechanisms, one ofeach pair being exclusively used for the X-axis directional motion, andthe other for the Y-axis directional motion.

A fifth object of the invention is to provide a cloth supporting frameadapted for use with the abovementioned embroidering machines, which ischaracterised by that it is light in weight, easy to move, andconvenient for cloth to be applied to or removed from while it is simplein structure, free from trouble, and may be manufactured at low costs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partlybroken away to show a unit mechanism which constitutes an essential partof the X- and Y- axis directional drive system to be equipped on anembroidering machine according to the present invention;

FIG. 2 is a sectional view taken on line II II of FIG.

FIG. 3 is a sectional view taken on line III III of FIG. 1;

FIG. 4 is a schematic view showing belt members trained around pulleys;

FIG. 5 is a schematic view showing a pair of unit mechanisms connectedto each other to be used for the X-axis drive.

FIG. 6 is a top plan view of the same mechanisms of FIG. 5;

FIG. 7a is a front view showing a rotary drive mechanism used in thepresent invention;

FIG. 7b is a top plan view, partly broken away, to show the samemechanism of FIG. 7a;

FIG. 8 is a schematic view showing belt members trained around pulleysin the rotary drive mechanism;

FIG. 9 is a schematic bottom plan view showing the relationship betweenthree movable shafts and a moving plate,

FIG. 10 is a rear view showing an embroidering machine according to theinvention;

FIG. 11 is a schematic sectional view showing the same embroideringmachine of FIG. 10',

FIG. 12 is a top plan view showing a cloth supporting frame according tothe invention;

FIG. 13 is an enlarged sectional view taken on line II II of FIG. 12;

FIG. 14 is an enlarged sectional view taken on line III III of FIG. 12;and

FIG. [5 is an enlarged sectional view showing cloth to be embroidered onin engagement with fastening plnS.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. 1 4,numeral 1 designates a frame, 2 and 3 represent stationary shaftsvertically fixed on the right and left ends of the frame 1 respectively,and 4, 5 and 6, 7 indicate pairs of pulleys mounted on the stationaryshafts 2 and 3 respectively, each pair of pulleys being rotatablydisposed one above the other. At the both upper and lower ends of eachof the pulleys 4 7 are respectively formed two guide grooves a, b.Numerals 8 and 9 are a guide shaft and a guide rail respectively, whichare arranged parallel with each other, extending between the fixedshafts 2, 3 of the frame I. Numeral I designates a slider which isslidably mounted on the guide shaft 8 through a ball bush (linear ballbearing) I2 with its sliding groove II slidably receiving the guide rail9. A movable shaft 13 is vertically mounted on the slider 10 andpositioned on a line extending between the fixed shafts 2 and 3.Independently rotatably fitted on the movable shaft I3 are pulleys l4,l5, and 16 which are arranged one above another, and are each providedwith two guide grooves a, b at its upper and lower ends as is the casewith the pulleys 4 7. The grooves a and b of each pulley are integrallyformed so that they are necessarily rotated in the same direction. Beltssuch as wires l7, 18 are trained around these pulleys (These belts l7,18 are omitted from FIGS. 1, 2, and 3), and have their ends secured tothe frame 1 by means of fastening means 19, 20 fixed on the frame. 21and 22 are guide pulleys.

An example of engagement of the belts 17, 18 around the pulleys is shownin FIG. 4. In this drawing, one belt 17 with its one end secured to thefastening means 19 is first trained around the pulley 14 in the guidegroove b thereof to then pass over the guide groove a of the pulley 4,and further travels over pulleys in the order of 1515, 50, 16b, andguide pulley 21, while another belt 18 with its one end secured to thefastening means 20 passes over pulleys in the order of 14a, 6a, 150, 7a,160 and guide pulley 22. With this arrangement, the guide grooves b ofthe pulleys 4 7 are not in use. Further, all the pulleys need not haveguide grooves.

One set of said unit mechanism is used for X-axis drive, and two sets, Aand B for Y-axis drive. An example of the Y-axis drive is shown in FIGS.and 6 in which the unit mechanisms A and B are connected to each otherby means of belts I7, 18 which run in connection with both the unitmechanisms A, B in a fashion that they have their respective free endsintegrally tied together at the intersecting point between the unitmechanisms. Provided between the two unit mechanisms in engagement withthe belt 17 is a rotary drive means 23 which serves to move the belt 17backward or forward. In FIG. 6, if the rotary drive means 23 is rotatedclockwise, the belt 18 of the unit mechanism A is pulled by the means 23toward the unit mechanism B, thus to downwardly drive the movable shaft13. This movement of the movable shaft 13 causes the belt 17 of the unitmechanism B to be pulled toward the unit mechanism A so that also themovable shaft 13 of the unit mechanism B is driven downward. In thiscase, the displacements of both the movable shafts 13, I3 are equal toeach other. If the rotary drive means 23 rotates counterclockwise, boththe movable shafts l3, 13 are upwardly driven by the same displacement,for the same reason as mentioned above.

In FIGS. 70, 7b, and 8, numeral 24 designates a driving wheel adapted tobe rotated by drive motor 53 (FIG. 25 a driven wheel, 26 a guide pulley,27 an endless loop of driving belt aroung the drive pulley 24, thedriven pulley 25, and the guide pulley 26, 28, 30 rotary pulleys bothprovided with respective four guide grooves c, d, e, f, 29 a pulleyhaving upper and lower guide grooves g, h, and 3], 32, 33, 34 guidepulleys for the belts 17, 18, the guide pulleys 3] and 34 being providedwith guide grooves, i, j at the upper and lower ends thereofrespectively. Numeral 35 is a brake means for braking the rotation ofthe pulley 29, and 36 and 37 clutch means for transmitting the rotationof the driven pulley 29 to the rotary pulleys 28, 30. Said rotary drivemeans 23 are used for both the X- and Y- axis drives (one is shown inFIG. 7), as designated respectively by 23X and 23Y in FIG. 10. In theembodiment of FIG. 10 the rotary drive means 23X and 23Y are driven by asingle driving source, but may be driven by separate driving sources, ifdesired.

FIG. 9 is a bottom plan view schematically showing the relationshipbetween three movable shafts 13 of the X- and Y-axis drive means and themoving plate 38 adapted to be moved in the longitudinal, transverse, ordiagonal directions by means of said movable shafts. In this drawing,l3Y represents a movable shaft adapted to move the moving plate 38 inthe Y-axis directions (i.e., in the upward and downward directions), and13X a movable shaft adapted to move the same plate 38 in the X-axisdirections, both the movable shafts being fitted in guide rails 39( and39X respectively. 40 is a ball bearing mounted on the, movable shaft 13for smoothing the movement of the movable shaft 13 with respect to theguide rail 39.

The relationship between the movable shaft 13 and the moving plate 38 isshown in FIGS. 2 and 3. This moving plate 38 is used for moving a clothsupporting frame 4] over which the cloth to be embroidered on is appliedin a supported manner. In FIG. 3, numeral 42 denotes a hook jointsecured to the moving plate 38 through a screw means 43, 44 a thumbscrew for fixing the cloth supporting frame to the moving plate 38through the hook joint 42, and 45 a bearing ball secured to theunderside of the cloth supporting frame 41 for smoothing the movement ofthe frame 4! with respect to a base plate 46.

FIG. 10 is a rear view showing an embroidering machine according to theinvention which is provided with the above-mentioned X- and Y- axisdirectional drive systems, and FIG. 11 is a sectional schematic view ofthe same. In these views, numeral 47 represents a plurality of machinebodies arranged side by side over the base plate 46, 48 a support bar oftubular structure spanning between support frames 49a, 4% which areerected on the right and left ends of the base plate 46, 50 an elongateangled member of L-shaped cross section, which is bridged between thesupport frames 49a, 49b in parallel relation with the support bar 48, 51and 52 members of channel-like sections integrally secured to the outersurfaces of an angled member 50 at right angles to each other, 56 adrive shaft for vertically reciprocating a needle, and 57 a drive shaftfor moving a thread take-up lever, said drive shafts 56, 57 beingbridged between the support frames 49a, 49b to be actuated by a givendrive means accomodated within the support frames. The above-describedmachine bodies inclusive of their drive means may be of a conventionaltype or the like.

Next, description is made of an embroidering cloth support frame overwhich embroidering cloth is to be applied. If the cloth to beembroidered on is loosened or has some folds, precise finish may neverbe expected, no matter how excellent the drive mechan'um may be. Forthis reason, improvements have been made to the cloth support frame bythe present inventor. In the following will be described details of theimprovements with reference to FIGS. I2, l3, l4 and 15.

In these drawings, numeral 101 represents a frame body made of a thinmetal plate such as duralumin, which has right and left side edgeportions 102 inwardly folded into channel-like shapes, and front andrear end edges I03 inwardly folded to form erect portions 104 and slopedportions extending from the erect portions. These folded side edges 102,erect portions 104 (shown in F IG. I 3 and sloped end edges 103 serve toenhance the rigidity of the frame body I] and prevent deformation of thesame body. Numeral I designates a number of first fastening pins closelyplanted over base members 106 made of relatively thick cloth orthe likeand applied on the upper surfaces of the sloped portions 103. Each pin105 has its top end fonned as a sharp blade 105a and has its upperportion of approximately one third of its whole length upwardly bent(see FIG. I5).

The support frame, with the above-described structure, permitsembroidering cloth to be applied thereover with much easiness.

Numeral 108 designates two elongated foundation plates secured to theframe body 101 near the opposite side edges thereof by butterfly nuts.

Along each foundation plate 108 are erected in a line a plurality ofsecond fastening pins 110 which are adapted to penetrate through an endportion of the cloth 107 to secure it to the foundation plate 108 (SeeFIG. 14).

Numeral 111 represents a caster provided under the frame body 101, 112 ascrew fixing the base member to the sloped edge portion 103, 1 13 atable, 1 14 a connector connecting the cloth supporting frame 101 to adrive means 115 (Only a part is shown, and its type and structure areoptional), 116 a setscrew, 117 a recess formed by folding the slopededge portion 103 which permits insertion of a finger thereinto thus tofacilitate engagement and disengagement of the cloth with respect to thepins 105, and 118 an opening.

FIGS. 13 and 14 show an example of application of embroidering clothwith respect to the present cloth frame 101. To engage the cloth 107with the pins 105, first the cloth 107 is applied over the blades 1050of the pins 105, and then is forced in the direction of bending of theblades (i.e., in the arrow A direction of FIG. 15) to be followed bypulling it backward or in the opposite direction to that of bending ofthe blades (In practice, the cloth need not be so strongly pulled, sinceit moves backward by itself by force of its restitution). Thus, the pinshave been thrusted through the cloth, as shown by B. Positive thrustingof fastening pins with respect to cloth may be ensured by the provisionof blades 1050 at the tops of the pins 105.

Further, the sloped edge portions I03 have elasticity enough toeffectively serve to ensure the positive engagement of the cloth 107 bythe pins 105, particularly with uniform tension applied over the wholecloth. This engagement will be effectively enhanced by clamping togetherthe mutually coupled cloth and fastening pins and the sloped edgeportion with a clip. The cloth 107 may be easily disengaged from thepins 105 merely by separating the cloth from the pins in a peelingmanner.

The embroidering machine and embroidering cloth frame according to theinvention are of the aforedescribed constructions. As described, themovement of the movable shafts 13 for moving the moving plate 38 iseffected by traction of the belts l7, 18, which traction power isgenerated by actuation of the drive wheel 24 and the clutch means 36,37. That is, when the drive wheel 24 is actuated, the driven wheels 25,25 are rotated via the driving belt 27, but since in a normal conditionthe clutch means 36, 37 are not in action, power is not transmitted tothe rotary pulleys 28, 30 and therefore the joined belts 17, 18 are nottracted. If in FIGS. 7a, 7b the drive wheel 24 is supposed to rotateclockwise and in FIG. 8 the clutch means 36 is actuated, the rotarypulley 28 is rotated to move the belts from the guide pulley 31 towardthe guide pulley 34. Inversely, if the clutch means 37 is actuated, therotary pulley 30 .is rotated to move the belts from the guide pulley 34toward the guide pulley 31. In this arrangement, the brake means 35 isutilized to instantly stop the belts. In this example, the clutch means36, 37 and the brake means 35 are numerically controlled. For thispurpose, a linear scale is provided right under the guide shaft 8, whichscale is read by a censor to determine the difference between adirective value and an actual value, and compensation is made for thedifference thus obtained.

As described, the automatic embroidering machine according to theinvention accomplishes its objects in a fmhion that the rotary drivemeans 23X, 23Y are actuated to tract the belts 17, 18 which, in turn,move the movable shafts 13X, 13! together with the slider, thus todisplace the moving plate 38 in frontward or rearward directions and inrightward or leftward directions. In FIG. 9, when the movable shaftsl3Y, l3Y move to displace the moving plate 38 in upward or downwarddirections or Y-axis directions, the movable shaft 13X correspondinglymoves within the guide rail 39X in the same directions. When the movableshaft 13X moves to displace the moving plate 38 in rightward or leftwarddirections (or in X-axis directions), the movable shafts 13Y, I3Ycorrespondingly move along the guide rails 39Y, 39Y in the samedirections, respectively.

Further, it goes without saying that when the moving plate 38 is to bedisplaced obliquely, all the movable shafts 13X, 13Y, 13Y should bemoved simultaneously. The present invention has some advantages: first,the displacement of the unit mechanism with respect to the machine formoving the embroidering cloth is only a small percentage of the drivingamount of the rotary drive means (The unit mechanism in the drawings hasa displacement of one-sixth of the driving amount of therotary drivemechanism. That is, in FIG. 4, if the free end of the belt 18 around theguide pulley 22 is pulled by 6 cm, the pulleys 14, 15, 16 (of themovable shafts) come nearer to the pulleys 7, 6 by 1 cm, as a result ofthe arrangement of three turns of the belt 18 between the pulleys 16,l5, l4 and the pulleys 7, 6, which means far higher precision ofmovement of the present embroidering machine than the conventionalembroidering machine mechanism employing racks and pinions, or the like.Secondly, in FIG. 6, the belt 17 between the pulleys 4, 5 and thepulleys 14, 15, 16 of the unit mechanism A and between the pulleys 6, 7and the pulleys 14, I5, 16 of the unit mechanism 8 is, when the brakemeans is actuated, always under the loaded and strained stateirrespective of the direction of rotation of the rotary drive means 23.

While, there may be a slight looseness on the belt 18 depending upon therotating direction of the rotary drive means 23 (In FIG. 8, when therotary drive means 23 rotates clockwise, looseness occurs on the belt inthe unit mechanism B. But, this looseness is invisibly small and merelylatent in the belt). However, the looseness only causes a slight delayin the movement of the slider at the moment the rotary drive means 23gets reversed in rotation, but never affects the resulting displacements of the two sliders. Therefore, the synchronization of them isvery precise, and the Y-axis drive of the moving plate has all thehigher precision. Particularly, unless said Y-axis drive is precise,there will occur considerable discrepancies in the resultingembroideries between the machine bodies on the right and left ends.Thus, the above-mentioned advantage is of much significance. The thirdadvantage is that when one belt is subjected to traction to rotate onepulley, the traction power is transmitted to the other belt which is inconnection with said pulley so that there will never occur a partialelongation of only one of the belts, thus ensuring high powertransmission speed and high response to result in finer finish of theembroideries. The fourth advantage is that for the X-axis drive, theguide rails 39Y, 39Y are moved with the movable shafts 13Y, l3Y, thusensuring rectilinear motion of the moving plate, and the fifth is thatbecause of the arrangement of the rotary drive mans 23X for the X-axisdrive and 23Y for the Y-axis drive independently from each other, thusfacilitating the designing and working of the machine and enablingreduction in the manufacturing cost. Such arrangement will further leadto easier repair, maintenance, and inspection of the product, since inthe event of an accidental cutting of the transmission belt 27, forfinding the cause, it will be sufficient to inspect only either of therotary drive means 23X, 23Y to which the out transmission belt 27belongs.

A further advantage is that the belts l7, 18 are trained, respectively,around a plurality of grooves (four grooves in the drawings) of thepulleys 28, 30 in connection with the clutches 36, 37, thus being freefrom slipping and consequently precise in movement. As a seventhadvantage, the embroidering machine according to the invention is simplein construction, easy to control and inspect, and excellent in enduranceen bugh to maintain its precision for a long time. A still furtheradvantage is that the present embroidering machine uses a clothsupporting frame of a seamless solid construction made of a single partwhich is very lightweight, and may be operated at high speeds. Anotherfeature of the cloth supporting frame is that the side edge portions 102and the end edge portions 103 are folded as specified hereinbefore,which results in the increased rigidity of the whole frame body andsufficient elasticity of the sloped end portions 103 so that uniformtension are spread over the embroiden'ng cloth applied around the frame,thus preventing partial loosening of the cloth as well as facilitatingmountinig or dismounting of the cloth with respect to the frame. Thus,the present cloth frame has excellent working property.

As this invention may be embodied in several forms without departingfrom the spirit of essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, since thescope of the invention is defined by the appended claims rather than bythe description preceding them, and all changes that fall within thespirit and scope of the claims, or equivalence of such spirit and scopeare therefore intended to be embraced by the claims.

What I claim is:

l. A synchronous drive system adapted for industrial use, andessentially constituted by first and second unit mechanisms, eachcomprising:

first and second stationary shafts arranged in spaced relation to eachother, each having one or more pulleys arranged one above another andeach provided with a plurality guide grooves;

a slider means mainly composed of a movable shaft arranged between saidfirst and second stationary shafts, said movable shaft having aplurality of pulleys which are disposed one above another and are eachprovided with a plurality of guide grooves;

first and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shaft in a fashion trained around the guide groovesthereof, so that each pulley of the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by traction of the belts,said first and second belt members of the first unit mechanism havingthe free ends thereof integrally connected, respectively, to the freeends of the first and second belt members of the second unit mechanism,said drive system further including a rotary drive means which engageswith either of the first and second belt members to draw the same.

2. An X- and Y-axis drive system comprising a first unit mechanism forX-axis directional drive, second and third unit mechanisms for Y-axisdirectional drive, each unit mechanism comprising:

first and second stationary shafts arranged in spaced relation to eachother, each having one or more pulleys arranged one above another andeach provided with a plurality of guide grooves;

a slider means mainly composed of a movable shaft arranged between saidfirst and second stationary shafts, said movable shaft having aplurality of pulleys which are disposed one above another and are eachprovided with a plurality of guide grooves; and

first and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shafl in a fashion trained around the guide groovesthereof, so that each pulley of the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by the traction of thebelt members, the first unit mechanism for X-axis drive having the freeends of the first and second belt members thereof connected to eachother, the second unit mechanism for Y-axis having the free ends of thefirst and second belt members thereof connected to the free ends of thefirst and second belt members of the third unit mechanism for Y-axisdrive.

each said X- and Y- axis drive system further comprising a first rotarydrive means which engages with either of the first and second beltmembers of the first unit mechanism to draw the same, and a secondrotary drive means which engages with at least one of the first andsecond belt members of the second and third unit mechanisms to draw thesame.

3. An embroidering machine carrying a plurality of machine bodies andessentially constituted by a plurality of X- and Y- axis drive systemseach composed of a first unit mechanism for X-axis directional drive,and second and third unit mechanisms for Y-axis directional drive, eachunit mechanisms comprising:

first and second stationary shafts arranged in spaced relation to eachother, each having one or more pulleys arranged one above another andeach provided with a plurality of guide grooves;

a slider means mainly composed of a movable shaft arranged between saidfirst and second stationary shafts, said movable shaft having aplurality of pulleys which are disposed one above another and are eachprovided with a plurality of guide grooves; and

first and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shaft in a fashion trained around the guide groovesthereof, so that each pulley of the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by the traction of thebelts, the first unit mechanism having the free ends of the first andsecond belt members thereof connected to each other, the second unitmechanism having the free ends of the first and second belt membersthereof connected to the free ends of the first and second belt membersof the third unit mechanism,

each said X- and Y- axis drive system including a first rotary drivemeans which engages with either of the first and second belt members ofthe first unit mechanism to draw the same, and a second rotary drivemeans which engages with at least one of the first and second beltmembers of the second and third unit mechanism to draw the same;

said embroidering machine further including:

a base plate carrying said machine bodies and on which the unitmechanisms for X- and Y- axis drive are mounted;

a plurality of moving plates each having X- and Y- axis guide railsarranged in engagement with the movable shafts of the unit mechanismsfor X- and Y- axis drive in a fashion that each said moving plate ismovable in X-, Y- axis and oblique directions in accordance with themovement of the movable shafts; and

a plurality of frames each supporting cloth to be embroidered on by oneof said machine bodies.

4. An embroidering machine adapted for industrial use, carrying aplurality of machine bodies and essentially constituted by a pluralityof X- and Yaxis direc tional drive system each comprising a first unitmechanism for X-axis directional drive, second and third unit mechanismsfor Y-axis directional drive, each unit mechanism comprising:

first and second stationary shafts arranged in spaced 6 relation to eachother, each having one or more pulleys arranged one above another andeach provided with a plurality of guide grooves;

a slider means mainly composed of a movable shaft arranged between saidfirst and second stationary shafts, said movable shaft having aplurality of pulleys which are disposed one above another and are eachprovided with a plurality of guide grooves; and

first and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shaft in a fashion trained around the guide groovesthereof, so that each pulleyoof the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by the traction of thebelt members, the first unit mechanism having the free ends of the firstand second belt members thereof connected to each other, the second unitmechanism having the free ends of the first and second belt membersconnected to the first and second belt members of the third unitmechanism,

each said X- and Y-axis drive system further comprising first and secondrotary drive means each composed of:

a driving wheel;

first and second driven wheels;

an endless loop of transmission belt trained around said driving wheeland first and second driven wheels in a fashion that said driven wheelsare rotated in opposite directions to each other;

first and second rotary pulleys mounted, respectively,

on said first and second driven wheels;

first and second clutch means engaged, respectively, with said first andsecond driven pulleys, and first and second rotary wheels, said clutchmeans being actuated to allow the rotary pulleys to be rotated in eitherdirections,

said first rotary means being in engagement with the first unitmechanism in a fashion that said mutually connected free ends of thefirst and second belt members of the first unit mechanism are trainedaround said rotary pulleys of the first rotary means, said second rotarymeans being in engagement with the second and third unit mechanisms in afashion that the first and second belt members of the second and thirdunit mechanisms mutually connected to each other at the free endsthereof are trained around said rotary pulleys of the second rotarymeans,

said embroidering machine further including:

a base plate carrying said machine bodies and on which the unitmechanisms for X- and Y-axis directional drive are mounted;

a plurality of moving plates each having X- and Y- axis guide railsarranged in engagement with the movable shafts of the unit mechanismsfor X- and Y-axis directional drive in a fashion that each said movingplate is movable in X-, Y-axis and oblique directions in accordance withthe movement of the movable shafts; and

a plurality of cloth frames each supporting cloth to be embroidered onby one of said machine bodies.

5. A cloth supporting frame for use with an embroidering machineaccording to any of the preceding claims, comprising: a frame bodyhaving opposite side edge portions inwardly folded into channel shapes,and

opposite end portions inwardly folded into erect porcloth to bestretched over the frame from said sloped tions and sloped portionsextending from the erect poredge portions to the underside of the framebody with tions; and a number of fastening pins closely planted an endof the cloth caught by said fastening pins. over said base membersthereby allowing embroidering

1. A synchronous drive system adapted for industrial use, andessentially constituted by first and second unit mechanisms, eachcomprising: first and second stationary shafts arranged in spacedrelation to each other, each having one or more pulleys arranged oneabove another and each provided with a plurality guide grooves; a slidermeans mainly composed of a movable shaft arranged between said first andsecond stationary shafts, said movable shaft having a plurality ofpulleys which are disposed one above another and are each provided witha plurality of guide grooves; first and second belt members each havingits one end secured to a stationary fastening means, said belt membersbeing in engagement with the pulleys of said first and second stationaryshafts and the pulleys of the movable shaft in a fashion trained aroundthe guide grooves thereof, so that each pulley of the movable shaft isin engagement with both the belt members, the slider means thus beingadapted to move towards the first or second stationary shafts bytraction of the belts, said first and second belt members of the firstunit mechanism having the free ends thereof integrally connected,respectively, to the free ends of the first and second belt members ofthe second unit mechanism, said drive system further including a rotarydrive means which engages with either of the first and second beltmembers to draw the same.
 2. An X- and Y-axis drive system comprising afirst unit mechanism for X-axis directional drive, second and third unitmechanisms for Y-axis directional drive, each unit mechanism comprising:first and second stationary shafts arranged in spaced relation to eachother, each having one or more pulleys arranged one above another andeach provided with a plurality of guide grooves; a slider means mainlycomposed of a movable shaft arranged between said first and secondstationary shafts, said movable shaft having a plurality of pulleyswhich are disposed one above another and are each provided with aplurality of guide grooves; and first and second belt members eachhaving its one end secured to a stationary fastening means, said beltmembers being in engagement with the pulleys of said first and secondstationary shafts and the pulleys of the movable shaft in a Fashiontrained around the guide grooves thereof, so that each pulley of themovable shaft is in engagement with both the belt members, the slidermeans thus being adapted to move towards the first or second stationaryshafts by the traction of the belt members, the first unit mechanism forX-axis drive having the free ends of the first and second belt membersthereof connected to each other, the second unit mechanism for Y-axishaving the free ends of the first and second belt members thereofconnected to the free ends of the first and second belt members of thethird unit mechanism for Y-axis drive. each said X- and Y- axis drivesystem further comprising a first rotary drive means which engages witheither of the first and second belt members of the first unit mechanismto draw the same, and a second rotary drive means which engages with atleast one of the first and second belt members of the second and thirdunit mechanisms to draw the same.
 3. An embroidering machine carrying aplurality of machine bodies and essentially constituted by a pluralityof X- and Y-axis drive systems each composed of a first unit mechanismfor X-axis directional drive, and second and third unit mechanisms forY-axis directional drive, each unit mechanisms comprising: first andsecond stationary shafts arranged in spaced relation to each other, eachhaving one or more pulleys arranged one above another and each providedwith a plurality of guide grooves; a slider means mainly composed of amovable shaft arranged between said first and second stationary shafts,said movable shaft having a plurality of pulleys which are disposed oneabove another and are each provided with a plurality of guide grooves;and first and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shaft in a fashion trained around the guide groovesthereof, so that each pulley of the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by the traction of thebelts, the first unit mechanism having the free ends of the first andsecond belt members thereof connected to each other, the second unitmechanism having the free ends of the first and second belt membersthereof connected to the free ends of the first and second belt membersof the third unit mechanism, each said X- and Y- axis drive systemincluding a first rotary drive means which engages with either of thefirst and second belt members of the first unit mechanism to draw thesame, and a second rotary drive means which engages with at least one ofthe first and second belt members of the second and third unit mechanismto draw the same; said embroidering machine further including: a baseplate carrying said machine bodies and on which the unit mechanisms forX- and Y- axis drive are mounted; a plurality of moving plates eachhaving X- and Y- axis guide rails arranged in engagement with themovable shafts of the unit mechanisms for X- and Y- axis drive in afashion that each said moving plate is movable in X-, Y- axis andoblique directions in accordance with the movement of the movableshafts; and a plurality of frames each supporting cloth to beembroidered on by one of said machine bodies.
 4. An embroidering machineadapted for industrial use, carrying a plurality of machine bodies andessentially constituted by a plurality of X- and Y-axis directionaldrive system each comprising a first unit mechanism for X-axisdirectional drive, second and third unit mechanisms for Y-axisdirectional drive, each unit mechanism comprising: first and secondstationary shafts arranged in spaced relation to each other, each havingone or more pulleys arranged one above another and each provided with aplurality of guide grooves; a slider means mainly composed of a movableshaft arranged between said first and second stationary shafts, saidmovable shaft having a plurality of pulleys which are disposed one aboveanother and are each provided with a plurality of guide grooves; andfirst and second belt members each having its one end secured to astationary fastening means, said belt members being in engagement withthe pulleys of said first and second stationary shafts and the pulleysof the movable shaft in a fashion trained around the guide groovesthereof, so that each pulleyoof the movable shaft is in engagement withboth the belt members, the slider means thus being adapted to movetowards the first or second stationary shafts by the traction of thebelt members, the first unit mechanism having the free ends of the firstand second belt members thereof connected to each other, the second unitmechanism having the free ends of the first and second belt membersconnected to the first and second belt members of the third unitmechanism, each said X- and Y-axis drive system further comprising firstand second rotary drive means each composed of: a driving wheel; firstand second driven wheels; an endless loop of transmission belt trainedaround said driving wheel and first and second driven wheels in afashion that said driven wheels are rotated in opposite directions toeach other; first and second rotary pulleys mounted, respectively, onsaid first and second driven wheels; first and second clutch meansengaged, respectively, with said first and second driven pulleys, andfirst and second rotary wheels, said clutch means being actuated toallow the rotary pulleys to be rotated in either directions, said firstrotary means being in engagement with the first unit mechanism in afashion that said mutually connected free ends of the first and secondbelt members of the first unit mechanism are trained around said rotarypulleys of the first rotary means, said second rotary means being inengagement with the second and third unit mechanisms in a fashion thatthe first and second belt members of the second and third unitmechanisms mutually connected to each other at the free ends thereof aretrained around said rotary pulleys of the second rotary means, saidembroidering machine further including: a base plate carrying saidmachine bodies and on which the unit mechanisms for X- and Y-axisdirectional drive are mounted; a plurality of moving plates each havingX- and Y-axis guide rails arranged in engagement with the movable shaftsof the unit mechanisms for X- and Y-axis directional drive in a fashionthat each said moving plate is movable in X-, Y-axis and obliquedirections in accordance with the movement of the movable shafts; and aplurality of cloth frames each supporting cloth to be embroidered on byone of said machine bodies.
 5. A cloth supporting frame for use with anembroidering machine according to any of the preceding claims,comprising: a frame body having opposite side edge portions inwardlyfolded into channel shapes, and opposite end portions inwardly foldedinto erect portions and sloped portions extending from the erectportions; and a number of fastening pins closely planted over said basemembers thereby allowing embroidering cloth to be stretched over theframe from said sloped edge portions to the underside of the frame bodywith an end of the cloth caught by said fastening pins.